The original loading was a 160 grain jacketed bullet at about 1960f/s, probably out of a 26 inch barrel. The cartridge was not released until 1895, when the barrel steel was changed to nickel steel to handle the higher temperatures of smokeless powder. There was a lead round around the turn of the century, called the .30-6-100. It was loaded with 6 grains of powder and had a 100 grain lead bullet. It duplicated BP .32-20 performance. The only 160 grain bullet today is the Leverevolution bullet, so you cannot duplicate the original round, unless you go to a custom bullet maker. Take your checkbook, left kidney, and firstborn along to pay for the privilege. You can certainly get close to the original load by downloading either 150 or 170 grain bullets just a bit. Any reloading manual will give suitable loads. There was an article in Rifle magazine several years ago where the writer did just that to match the sights of an English rifle he had gotten hold of.
